标题： 垂直磁化的磁性绝缘体中的室温强轨道矩 显示英文标题

标题： Room Temperature Strong Orbital Moments in Perpendicularly Magnetized Magnetic Insulator

摘要： 磁性系统中轨道磁矩和自旋磁矩之间的平衡是许多有趣现象的核心。 在这里，我们展示了铁氧体磁绝缘体铥铁石榴石（Tm₃Fe₅O₁₂）中存在一个大的轨道磁矩的实验证据，该轨道磁矩与其自旋磁矩相对抗。 利用元素特异性的X射线磁圆二色性（XMCD），我们确定主导轨道磁矩的主要贡献来自铥的4f轨道。 除了大的铥轨道磁矩外，有趣的是，我们的结果还揭示了O K边缘存在较小但明显的非零XMCD信号，表明与最近邻的铁原子存在额外的自旋-轨道耦合和交换相互作用。 未淬灭的轨道磁矩主要是导致g因子显著降低的原因，通常过渡金属中的g因子约为2，这是通过铁磁共振光谱独立测定的。 我们的研究结果揭示了Tm₃Fe₅O₁₂薄膜中g因子从300K时的1.7线性减少到200K时的1.56。 这些结果为f轨道在长程磁有序中的作用提供了关键见解，并激发了对轨道电子学的进一步探索。 显示英文摘要

摘要： The balance between the orbital and spin magnetic moments in a magnetic system is the heart of many intriguing phenomena. Here, we show experimental evidence of a large orbital moment, which competes with its spin counterpart in a ferrimagnetic insulator thulium iron garnet, Tm3Fe5O12. Leveraging element-specific X-ray magnetic circular dichroism (XMCD), we establish that the dominant contribution to the orbital moment originates from 4f orbitals of Tm. Besides the large Tm orbital moment, intriguingly, our results also reveal a smaller but evident non-zero XMCD signal in the O K edge, suggesting additional spin-orbit coupling and exchange interactions with the nearest neighbour Fe atoms. The unquenched orbital moment is primarily responsible for a significant reduction in g-factor, typically 2 in transition metals, as determined independently using ferromagnetic resonance spectroscopy. Our findings reveal a non-linear reduction in the g-factor from 1.7 at 300 K to 1.56 at 200 K in Tm3Fe5O12 thin films. These results provide critical insights into the role of the f orbitals in long-range magnetic order and stimulate further exploration in orbitronics.